get pull_spp() to work

[iantaylor-NOAA]

The pull_spp() function wasn't working because the https://github.com/pfmc-assessments/nwfscSurvey/blob/main/data/PullSpp.rda file contained a PullSpp data frame, not pull_spp. If you prefer to rename the data frame or get this working some other way, we can delete this pull request.

In the bigger picture, is the goal for everyone to use the pull_*() functions in the future and deprecate the older Pull*.fn() versions? If so, more guidance on that in the vignette or function documentation could be helpful.

[chantelwetzel-noaa]

The new pull request just merged into the main branch simplifies the code in that the older Pull* functions now call the newer pull_* function with a warning about the functions being deprecated. I don't recall why I did not choose to do that exact thing with the PullSpp.fn but I think I should modify it to be the same. In the pull_spp function it looks like I missed changing PullSpp to species in a place but there is also an issue with the species.rda file I created trying to mimic the PullSpp.rda.